Cutting oil composition



Patented Nov. 10, 1953 CUTTING OIL COMPOSITION Henry A. Ambrose, PennTownship, Allegheny County, and Oliver L. Brandes, Gibsonia, Pa.,assignors to Gulf Research & Development Company, Pittsburgh, Pa., acorporation of Delaware No Drawing. Application March 3, 1952, SerialNo. 274,678

3 Claims. (01. 252-485) This invention relates to a cutting oilcomposition and more particularly to an oil adapted "to be applied as athin high-speed jet into the angle between the work and the cutting edgeof a metal-working tool.

The use of cutting oils to carry off excess heat and to lessen frictioncreated during metalworking operations such as turning, boring, milling,and shaping, is recognized as necessary to the successful commercialoperation of such processes. Improved techniques in applying a cuttingfluid to the surface of the metal being worked have presented problemswhich heretofore have not been encountered.

The application of a cutting oil to a surface application of a cuttingoil in the form of a thin high-speed jet to the angle between the workand the tool increases the life of the tool while, at the same time, thesurface of the finished work is improved. When the cutting oil isapplied as a thin high-speed jet, the oil penetrates the extremely smallclearance between the work and relief surface of the tool withoutimpinging upon the heel of the tool or otherwise dissipating its energybefore reaching its destination. The prior cutting oil compositionswhich have been employed when the floodin technique is used are notentirely satisfactory when applied as a high-speed jet.

We have discovered that an improved cutting oil composition adapted tobe applied as a thin high-speed jet is obtained by incorporating in amajor amount of a mineral lubricating oil having a viscosity of about 70to about 300 SUS at 100 F. a minor amount of (1) a mineral lubricatingoil having a viscosity between about 100 and about 200 SUS at 210 F.,(2) a fixed fatty oil, and (3) the residue which remains after removalof the solvent from the extract obtained by extracting a petroleumdistillate oil We have found that the base oil for the cuttingcompositions of this invention should be a mineral oil fraction having aviscosity of about 70 to about 300 SUS at 100 F. The lower viscosityoils, i. e., those having a viscosity not greater than about SUS at 100F., which oils are satisfactory when the flooding technique is used, arenot satisfactory when the high-speed jet technique is employed. Forinstance, we have found that a cutting oil composition having as itsbase a mineral seal oil having a viscosity of about 35 SUS at 100 F.gave strikingly poorer results than a cutting oil composition having asits base a mineral oil having a viscosity of about 100 SUS at 100 F. Aparticularly advantageous mineral oil in the compositions of ourinvention is a light Texas oil, a typical example of which has an APIgravity of about at, a flash point of about 320 F., a fire point ofabout 355 F., a viscosity of about 100 SUS at 100 F., a color of about 2on the NPA scale,

and a pour point of about F. In the cutting oil compositions of thepresent invention, the to 300 SUS oils constitute at least 50 per centby weight of the total composition and advantageously are used inamounts of about '75 to about 98 per cent by weight.

A mineral lubricating oil having a viscosity of about 100 to about 200SUS at 210 F. is employed in the compositions of our invention toprovide a film of lubricant on the metal surface which is more stable tothe high temperatures encountered than the mineral oil which forms abase for the cutting oil compositions.

A lubricating oil which is particularly advan- 210 F. This highlyviscous oil component of the cutting oil compositions of our inventionis employed in an amount between about 1 and about 20 per cent byweight.

The fixed fatty oils used in the compositions of our invention areemployed primarily to increase the oiliness or lubricity of theresultant compositions and are customarily used in amounts between about0.5 and 15.0 per cent by weight.

Examples of the fixed fatty oils which may be used are lard oil, tallowoil, neats-foot oil, sperm oil, wool oil, whale oil, and the like. Ofthese oils, lard oil is particularly satisfactory. Instead of the animaloils we may substitute therefor fish oils or vegetable oils. The fishoils are generally less desirable because of their offensive odor. Thevegetable oils are less desirable than the animal oils because of theirtendency to oxidize and form gum at the temperatures encountered incutting operations. By using a suflicient amount of a scentin agent suchas pine oil, oil of citronella, and the like, the oifensive odor of thefish oils may be overcome. Likewise, by employing a suificient amount ofan oxidation inhibitor such as, for example, an amino phenol, analkylated phenol, an alkyl phosphite, and an alkylated phenol phosphiteor phosphate ester, the oxidation of the vegetable oils such as oliveoil, rapeseed oil, corn oil, and castor oil, may be minimized. For thispurpose the alkylphenyl phosphite esters, which are also effectiveextreme pressure agents, are particularly advantageous. Typicalcompounds within this class are tri- (tertiary-amyl-phenyl) -phosphiteand tri-butyl phosphite. When an oxidation inhibitor is employed, anamount between about 0.03 and about 5.0 per cent by weight may be used.The amount of a scenting agent employed will depend upon the oil and theparticular agent used, the amount ordinarily not exceeding about 0.1 percent by weight.

The residue which remains after removal of the solvent from the extractobtained by extracting a petroleum distillate oil with a solvent capableof removing polycyclic hydrocarbons and sulfur compounds from petroleumdistillate oils is incorporated in the compositions of the invention toincrease further the extreme pressure characteristics of thecompositions. Solvent refined extracts obtained from distillate oils andhaving viscosities of 55 to '70 SUS at 210 F. are most satisfactory. Thesolvent employed in treating the petroleum distillate oil to obtain theresidue may be furfural, nitrobenzene, sulfur dioxide, phenol, and thelike. The residue is advantageously used in an amount between about 1and about per cent by weight based on the weight of the totalcomposition. A typical resid ual product of this type has the following-Droperties:

Gravity, API 14.4 Flash point, F 365 Fire point, "F 1.. 435 Viscosity,SUS:

At 100 F 1222 At 210 F 61.8 Pour point, F +5 The cutting oilcompositions of this invention may contain other additive agents, ifdesired, to improve other specific properties without deleteriouslyaffecting the beneficial properties of the compositions. For example,wetting agents such as fatty acids and detergent sulfonates may beincorporated in the compositions to improve their properties for wettingthe metal surfaces with a similar composition prepared from an oil havina viscosity below about 70 SUS at 100 F. is illustrated in Table I. Thetool life data were obtained when cutting A181 3140 steel, at a speed of140 surface feet per minute, and a depth of cut of 0.150 inch.

Table I Composition A B G D Mineral Oil Basaparts by weight 05 85 95 95Lard Oil do 2 6 2 2 Refined lubricating oil having a viscosity of 150SUS at 210 F. and a pour point of +5 F.

parts by weight.. 2 6 2 2 Napthenic fllrfural extract of coasta1distillate, '55 to 70 SUS at 210 F. and a pour point of +5 F.

parts by weight 1 3 1 1 Tool Life, minutes 340 335 325 210 Typicalproperties of the Mineral Oil Base:

Gravity, API 24. 1 24. 1 25. 8 41.0 Viscosity, SUS. at 100 F. 103. 5103. 5 74 38 Flash point, I.. 320 320 295 260 Fire point, F 355 355 345305 Your point, F.-. 45 belog 25 Color, NPA 1. 75 l. 75 1.5 1-

As can be noted from the tool life data, compositions of the invention,compositions A, B. and C, are strikingly superior to a composition notwithin the scope of the invention, .i. e. com.- position D.

Composition A represents a preferred embodiment of the invention and hasan API gravity of 24.5; viscosities of 114 SUS and 39.1 SUS at 100 and210 F., respectively; NPA color of 3+; a pour point of -57 F.; a flashpoint of 320 F.; and a fire point of 360 F.

The tool life tests referred to hereinabove were made on A181 3140 steelusing a high-speed steel (18-4-1) tool. In these tests the cuttingcompositions were directed in the form of a thin jet of cutting liquidat a velocity of about 260 feet per second and delivering 0.12 gallonper minute into the angle between the work and the tool. The thin jetwas obtained by passing the cutting composition through a small orifice(0.014 inch) in a nozzle which was mounted on the carriage of the lathe.In the present tests a one-half inch tool bit was employed. The cuttingcompositions were supplied to the nozzle at a temperature of about 100F. under a pressure of 400 pounds per square inch. In these tests aconventional overhead stream of cutting composition circulating about '3gallons per minute was also employed.

While the invention has been described above with reference to certainspecific embodiments thereof by way of illustration, it is to beunderstood that the invention is not limited to such embodiments exceptas hereinafter defined in the appended claims.

We claim:

1. An improved cutting oil composition adapted to be applied as a thinhigh-speedjet consisting of at least per cent by weight of a minerallubricating oil having a viscosity of about to about 300 SUS at F.;about 1 to about 20 per cent by weight of a mineral lubricating oilhaving a viscosity between about 100 and about 200 SUS at 210 F.-; about0.5 to about 15 per cent by weight of a fixed fatty oil; and about 1 toabout 10 per cent by weight of the residue which remains after removalof the solvent from the extract obtained by extracting a petroleumdistillate oil with a solvent capable of removing polycyclichydrocarbons and sulfur compounds from petroleum distillate oils, saidresidue having a viscosity between about 55 and about '70 SUS at 210 F.

2. An improved cutting oil composition adapted to be applied as a thinhigh-speed jet consisting of about '75 to about 98 per cent by weight ofa mineral lubricating oil having a viscosity of about 70 to about 300SUS at 100 F.; about 1 to about per cent by weight of a minerallubricating oil having a viscosity between about 100 and about 200 SUSat 210 about 0.5 to about 15 per cent by weight of lard oil; and about 1to about 10 per cent by weight of the residue which remains afterremoval of the solvent from the extract obtained by extracting apetroleum distillate oil with a solvent capable of removing polycyclichydrocarbons and sulfur compounds from petroleum distillate oils, saidresidue having a viscosity between about and about SUS at 210 F.

3. An improved cutting oil composition adapted to be applied as a thinhigh-speed jet consisting of about per cent by Weight of a minerallubricating oil having a viscosity of about SUS at 100 F.; about 2 percent by weight of a mineral lubricating oil having a viscosity of aboutSUS at 210 F.; about 2 per cent by weight of lard oil; and about 1 percent by weight of the residue which remains after removal of the solventfrom the extract obtained by extracting a petroleum distillate oil witha solvent capable of removing polycyclic hydrocarbons and sulfurcompounds from petroleum distillate oils, said residue hav ing aviscosity between about 55 and about 70 SUS at 210 F.

HENRY A. AMBROSE.

OLIVER L. BRANDES.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,010,606 Moser Aug. 6, 1935 2,308,427 Roehner Jan. 12, 19432,453,708 Hughes Nov. 16, 1948 2,470,913 Bjorksten May 24, 1949

1. AN IMPROVED CUTTING OIL COMPOSITION ADAPTED TO BE APPLIED AS A THINHIGH-SPEED JET CONSISTING OF AT LEAST 50 PER CENT BY WEIGTH OF A MINERALLUBRICATING OIL HAVING A VISCOSITY OF ABOUT 70 TO ABOUT 300 SUS AT 100*F.; ABOUT 1 TO ABOUT 20 PER CENT BY WEIGTH OF A MINERAL LUBRICATING OILHAVING A VISCOSITY BEWEEN ABOUT 100 AND ABOUT 200 SUS AT 210* F.; ABOUT0,5 TO ABOUT 15 PER CENT BY WEIGHT OF A FIXED FATTY OIL; AND ABOUT 1 TOABOUT 10 PER CENT BY WEIGHT OF THE RESIDUE WHICH REMAINS AFTER REMOVALFO THE SOLVENT FROM THE EXTRACT OBTAINED BY EXTRACTING A PETROLEUMDISTILLATE OIL WITH A SOLVENT CAPABLE OF REMOVING POLYCYCLICHYDROCARBONS AND SULFUR COMPOUNDS FROM PETROLEUM DISTILLATE OILS, SAIDRESIDUE HAVING A VISCOSITY BETWEEN ABOUT 55 AND ABOUT 70 SUS AT 210* F.